SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75e32de2f925daa13a951b527b98d9ccf2eef26dd00c826a9d180231dad293b4' 
  AND token = '42EgueOUYtEBx5sLKcYxkS67KZ/PeSUZQsWM1iMvG8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}